1,721,040 research outputs found
Characterization of ETL 9357FLA photomultiplier tubes for cryogenic temperature applications
No full textWe carried out a careful evaluation of the performance of the large cathode area ETL 9357FLA photomultiplier tube operating at cryogenic temperature. The measurements were focused on evaluating the parameters which mainly characterize the operating performances of the device down to 77K and the spread of the distinctive features over 54 samples assembled in the ICARUS apparatus.The results that we obtained demonstrate that the photomultiplier is suited for light detection in such unconventional operating conditions, certifying this device for the direct measurement of scintillation light coming from noble-gas liquids in detectors dedicated to neutrino physics and dark matter research
Design, construction and tests of the ICARUS T600 detector
No full textWe have constructed and operated the ICARUS T600 liquid argon (LAr) time projection chamber (TPC). The ICARUS T600 detector is the largest LAr TPC ever built, with a size of about 500 tons of fully imaging mass. The design and assembly of the detector relied on industrial support and represents the applications of concepts matured in laboratory tests to the kton scale.The ICARUS T600 was commissioned for a technical run that lasted about 3 months. During this period all the detector features were extensively tested with an exposure to cosmic-rays at surface with a resulting data collection of about 30 000 events.The detector was developed as the first element of a modular design. Thanks to the concept of modularity, it will be possible to realize a detector with several ktons active mass, to act as an observatory for astroparticle and neutrino physics at the Gran Sasso Underground Laboratory and a second-generation nucleon decay experiment.In this paper a description of the ICARUS T600 is given, detailing its design specifications, assembly procedures and acceptance tests. Commissioning procedures and results of the technical run are also reported, as well as results from the off-line event reconstruction
Analysis of the liquid Argon purity in the ICARUS T600 TPC
No full textThe results reported in this paper are based on the analysis of the data recorded with the first half-module of the
ICARUS T600 liquid argon Time Projection Chamber (LAr TPC), during a technical run that took place on surface in
Pavia (Italy). We include results from the linearity, uniformity and calibration of the electronics, measurements on the
electron drift velocity in LAr at different electric fields, as well as the LAr purity achievement of the detector. Two
complementary techniques were used to measure the drift electron lifetime inside the active volume: the first, from the
data of a purity monitor, gives a measurement localized in space; the second, based on the study of the signals produced
by long minimum ionizing tracks crossing the detector, provides a LAr volume averaged value. Both methods yield
consistent results over the whole data taking period and are compatible with an uniform LAr purity over the whole
volume. The maximal drift electron lifetime value was recorded before the run stop and was about 1:8 ms: From an
interpretation of the observed drift electron lifetime as a function of time, we conclude that the adopted technology
would allow for drift distances exceeding 3 m
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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